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Show HN: Rhun, an open-source code editor written in assembly
rhun.apptool

Show HN: Rhun, an open-source code editor written in assembly

Rhun is a small, fast open-source code editor written entirely in assembly, built around the idea that AI handles the heavy lifting of coding while the editor itself stays minimal. It includes tabs, syntax highlighting, fuzzy search, optional Vim mode, and 39 themes, plus the ability to run builds and shell commands alongside code; it integrates with Claude Code and Codex sessions (using the user's existing subscriptions) or local open-weight models to draft commit messages and follow agent sessions as they work.

TL;DR An assembly-written, minimalist code editor designed to sit alongside Claude Code and Codex agent sessions rather than replace them.
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What it claims

Rhun is a small code editor written in assembly. Its pitch is that AI agents do the heavy coding work, so the editor itself can stay light. The summary does not mention three things the page states:

  • Git workflow built in. You can review diffs, stage changes and commit inside the editor.
  • AI is optional. The page says so explicitly. Commit-message drafting can use local open-weight models, or Claude Code and Codex through your existing subscriptions.
  • Agents run beside your code. Coding agents run in the editor next to your code, alongside builds and shell commands, rather than only being watched.

How to use it

The source and releases are on GitHub at vshvedov/rhun.

On Linux and macOS, install from the terminal:

curl -fsSL https://github.com/vshvedov/rhun/releases/latest/download/install.sh | sh

On Windows, download the ZIP from releases, extract it and open rhun.exe.

Limits

  • No licence named. The page calls Rhun open source but does not say which licence. Check the repository before adopting or forking it.
  • Unreviewed install script. The install pipes a remote script from the latest release straight into sh. Read install.sh first if that matters in your environment.
  • No performance evidence. The page says "small" and "fast" but gives no binary size, startup time or memory figures.
  • No detail on several features:
  • which languages syntax highlighting supports
  • which CPU architectures the assembly targets
  • which local model runtimes or open-weight models work for commit drafting
  • how following Claude Code and Codex sessions works (for example, whether it reads session files or attaches to processes)
  • Marketing page only. There is no documentation on the page, so the feature list cannot be checked beyond these claims.

Organisations named here

  • Claude Code

Technologies named here

  • Rhun
  • Claude Code
  • Codex

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